3. Objectives
Introduce ports
Identify the different ports
Work with the IEEE 1394 bus
Configure IRQ
Troubleshoot ports
Chapter 10 Slide 3 of 20
4. Ports and show Introduction from CBT
Entry and exit point for data from
the system
Connects the system and a device
using a connecting cable
Located at the back or the front
side of the system case
Ports have different shapes and
sizes and you can not insert a plug
in the wrong port
You can just unplug a device that
is not used and plug in another
device in that port
Chapter 10 Slide 4 of 20
5. Port Symbols
Identifies the type of the port
Symbol Port
Serial / COM
Parallel
USB
IEEE 1394 / Firewire
PS/2 – Keyboard
PS/2 – Mouse
Line In
Line Out
Microphone
Joystick
Bluetooth
Chapter 10 Slide 5 of 20
6. Types of Ports
Types of
Ports
Serial Parallel DIN5 PS/2 Infrared Bluetooth USB Firewire
Chapter 10 Slide 6 of 20
8. Serial Port and show through CBT
Sends and receives one bit of data at a time
Known as the Communication or COM port
Has 9 or 25 pins
Connect devices such as the mouse, plotters and modems
Transmitting device sends a start bit then actual data byte
followed by a stop bit
Maximum cable length is 50 feet
If you need more serial ports, you can install multi I/O
card
Chapter 10 Slide 8 of 20
9. Parallel Port – I
Transmits eight bits of data at a time
Has 25 pins
Connects devices such as printers, scanners, external hard
drive and tape drive
You can get more parallel ports by installing an expansion
card
LPT1 uses IRQ7 and LPT2 uses IRQ5
Chapter 10 Slide 9 of 20
10. IEEE 1284
Compatibility Mode – used for directing data from
computer to peripheral (output only)
Nibble Mode – 4 bit (Input only)
Byte Mode – uses software drivers same as nibble
mode (8 bit)
Enhanced Parallel Port Mode (EPP) – it is
hardware driven and bi-directional, high speed
parallel port interface
Enhanced Capability Port Mode (ECP) – same as
EPP uses DMA
Chapter 10 Slide 10 of 20
11. Parallel Port – II
Different types of parallel ports are:
• Bidirectional – Uses byte and compatible mode for data
transmission
• Standard Parallel Port (SPP) - Uses nibble and
compatible mode for data transmission
• Enhanced Parallel Port (EPP) - Provides data transfer
speed of 500 Kb to 2 Mb of data per second. It is built
into super I/O chip or south bridge chip on motherboard
• Enhanced Capabilities Port (ECP) - Provides increased
data communication speed to connect printer or scanner
and supports DMA
Chapter 10 Slide 11 of 20
12. DIN 5
Used to connect the keyboard to the system
Known as the AT port
Uses 5 pins for connecting the device
Chapter 10 Slide 12 of 20
13. Pin Diagram of DIN5
AT keyboard connector (DIN5)
Connector Pin # Purpose
Pin 1 KBDCLK (clock)
Pin 2 KBDAT (data)
Pin 3 KBRST (reset, not used)
Pin 4 GND
Pin 5 VCC (+5V)
Chapter 10 Slide 13 of 20
14. PS/2 (Personal System/2)
Used to connect the keyboard and the mouse
Available in a color that matches the color of the device
plug
Uses 6 pins to connect the device
Mouse Port
Keyboard
Port
Chapter 10 Slide 14 of 20
15. Pin Diagram of PS/2
PS/2 keyboard connector (MINI-DIN6)
Connector Pin # Purpose
Pin 1 KBDAT (data)
Pin 2 not used
Pin 3 GND
Pin 4 VCC (+5V)
Pin 5 KBDCLK (clock)
Pin 6 not used
Chapter 10 Slide 15 of 20
16. Universal Serial Bus (USB)
Connects upto 127 devices to a single port
Supplies power to the device
Plug-and-play support
Maximum cable length is 30m thus you can connect 5
hubs to the USB
Has two different connections: connection A and
connection B
USB 1.0 – 1.5 Mbps, USB 1.1 – 12 Mbps and USB 2.0 –
480 Mbps
Chapter 10 Slide 16 of 20
18. Infrared Ports
Communicate with the system without using wires
Devices send out infrared signals that enter the system
through this port
Infrared Port
Chapter 10 Slide 18 of 20
19. Bluetooth Port
Allows wireless communication between devices within a
ranged distance
Uses 2.45 GHz frequency range for data communication
A Bluetooth adapter required for the computer and a
Bluetooth compatible device to communicate
Speed is 1 or 2 Mbps depending on the version
Chapter 10 Slide 19 of 20
20. IEEE 1394 Bus
Enables fast and high serial data transfer rate of upto 400
Mb per second
Connects and supplies power to the connected devices
such as printer, scanner, web camera and generally used
for transferring audio and video data from a camera to the
system
Known as FireWire by Apple and iLink by Sony
Chapter 10 Slide 20 of 20
21. S-Video Port
Short for Super-Video, a
technology for transmitting
video signals over a cable by
dividing the video information
into two separate signals: one
for color (chrominance), and
the other for brightness
(luminance). When sent to a
television, this produces
sharper images than composite
video, where the video
information is transmitted as a
single signal over one wire.
This is because televisions are
designed to display separate
Luminance (Y) and
Chrominance (C) signals. (The
terms Y/C video and S-Video
are the same.)
Chapter 10 Slide 21 of 20
22. DVI Monitor Port
Short for Digital Visual
Interface, in this case data is
transmitted using the transition
minimized differential signaling
(TMDS) protocol, providing a
digital signal from the PC's
graphics subsystem to the
display. The standard specifies
a single plug and connector that
encompass both the new digital
and legacy VGA interfaces, as
well as a digital-only plug
connector. DVI handles
bandwidths in excess of 160
MHz and thus supports UXGA
and HDTV with a single set of
links.
Chapter 10 Slide 22 of 20
23. eSATA
Benefits of eSATA:
• Up to 6 times faster than
existing external storage
solutions: USB 2.0, & 1394
• Robust and user friendly
external connection
• High performance, cost
effective expansion storage
• Up to 2 meter shielded
cables and connectors
• Applications: External
Direct Attached Storage for
notebooks, desktop,
consumer electronics and
entry servers.
Chapter 10 Slide 23 of 20
24. Interrupt Request (IRQ) - I
Used by devices to communicate with the
microprocessor
IRQ
Number
Typical Use
0 System timer
1 Keyboard
2 Interrupt for IRQs 8-15
3 Second serial port (COM2)
4 First serial port (COM1)
5 Sound card
Chapter 10 Slide 24 of 20
25. Interrupt Request (IRQ) - II
6 Floppy disk controller
7 First parallel port. Used by the printer or any
device using the parallel port.
8 Real-time clock
9 Open interrupt
10 Open interrupt
11 Open interrupt
12 PS/2 mouse / Network Card
13 Floating point unit/coprocessor. Only used for
internal signaling.
14 Primary IDE channel
15 Secondary IDE channel
Chapter 10 Slide 25 of 20
27. 6 Channel Sound Card
A new version sound card is
having 6 channels, which
support multi speaker output.
Can be easily installed on
available PCI slot through
PCI interface. Different
manufacturers have different
features for 6 channel sound
card. Some of them support
the features such as Direct
sound 3D and DSL based
Wavetable music synthesizer
and 3D positional audio. It
also contains a game port
which supports 3D surround
effect in games.
Chapter 10 Slide 27 of 20
28. Wireless LAN USB Adapter
Connects computer to wireless LAN
By using this adapter desktop, notebook and laptop users
can connect to a standard mobile network
Plugged to computer through a USB port
Data Transfer Rate is 54 Mbps
Chapter 10 Slide 28 of 20
29. Troubleshooting and show how to resolve IRQ
conflict practically
While using the device, errors may occur if there
is a problem with the I/O port
Different types of problems related with IO port:
• Device not working properly
• IRQ conflicts
Chapter 10 Slide 29 of 20
30. Serial or Parallel Cable Testing
Cable tester is used to
verify the connections of
the cables connected to
the computer. It is an
electronic device, which is
used to check the
connections in the cable.
Consists of a current
source, voltmeter and a
switching matrix. All the
contact points in the cable
are connected to a source
of current and a voltmeter
using a switching matrix.
Chapter 10 Slide 30 of 20
31. Summary – I
A port is used to connect the system and a device together,
using a connecting cable.
The ports have different shapes and sizes that prevent you
from connecting a device to the wrong port.
A serial port sends and receives one bit of data at a time.
The parallel port transmits eight bits of data at a time.
The PS/2 port is used to connect the keyboard and mouse to
the system.
The USB port connects and also supplies power to the device.
Chapter 10 Slide 31 of 20
32. Summary – II
Infrared ports enable wireless communication between the
device and the system.
IEEE 1394 enables fast and high speed data transfer between
the system and the connected devices.
Devices use the IRQ lines to communicate with the
microprocessor.
IRQ conflicts occur when two hardware devices use the same
IRQ line.
Chapter 10 Slide 32 of 20